Tiled display list

Abstract

A method for scaling including: obtaining an electronic document (ED) identifying a graphical feature; partitioning the ED into multiple tiles including a first tile and a second tile, where the graphical feature spans the first tile and the second tile; partitioning the graphical feature into a first fragment located solely within the first tile and a second fragment located solely within the second tile; adding the first fragment to a first display sub-list corresponding to the first tile; adding the second fragment to a second display sub-list corresponding to the second tile; receiving a first request to scale the ED specifying a resolution and a first region intersecting a subset of the plurality of tiles including the first tile but excluding the second tile; and generating, in response to the first request, a first scaled ED for the display device by rendering only the first display sub-list the resolution.

What is claimed is: 
     
       1. A method for scaling on a display device, comprising:
 obtaining an electronic document (ED) identifying a first graphical feature and a second graphical feature; 
 partitioning the ED into a plurality of tiles comprising a first tile and a second tile, wherein the first graphical feature spans the first tile and the second tile, and wherein the second graphical feature is located solely within the second tile; 
 partitioning the first graphical feature into a first fragment located solely within the first tile and a second fragment located solely within the second tile; 
 generating a first plurality of elemental vector objects for the first fragment; 
 adding the first plurality of elemental vector objects to a first display sub-list corresponding to the first tile; 
 generating a second plurality of elemental vector objects for the second fragment; 
 adding the second plurality of vector elemental objects and the second graphical feature to a second display sub-list corresponding to the second tile; 
 receiving a first request to scale the ED, wherein the first request specifies a resolution and a first region intersecting a subset of the plurality of tiles including the first tile but excluding the second tile; and 
 generating, in response to the first request, a first scaled ED for the display device by rendering the first display sub-list at the resolution without rendering the second display sub-list. 
 
     
     
       2. The method of  claim 1 , further comprising:
 receiving a second request to scale the ED, wherein the second request specifies a second region intersecting the second tile; and 
 generating, in response to the second request, a second scaled ED for the display device by rendering the second display sub-list. 
 
     
     
       3. The method of  claim 1 , wherein rendering the first display sub-list comprises:
 traversing the first display sub-list and scaling the first fragment based on the resolution specified in the first request. 
 
     
     
       4. The method of  claim 1 , wherein the ED is described in OOXML. 
     
     
       5. The method of  claim 1 , wherein the first tile and the second tile have different areas. 
     
     
       6. The method of  claim 1 , wherein the first display sub-list and the second display sub-list correspond to different sections of a master display list for the ED. 
     
     
       7. The method of  claim 1 , further comprising:
 converting, before receiving the first request to scale the ED, the first fragment and the second fragment into a color space of the display device, wherein the first graphical feature is an image. 
 
     
     
       8. The method of  claim 1 , wherein adding the second graphical feature to the second display sub-list comprises:
 generating, before receiving the first request to scale the ED, a vector outline for the second graphical feature, wherein the second graphical feature is a text character; and 
 adding the vector outline to the second display sub-list. 
 
     
     
       9. A non-transitory computer readable medium (CRM) storing instructions for scaling, the instructions comprising functionality for:
 obtaining an electronic document (ED) identifying a first graphical feature and a second graphical feature; 
 partitioning the ED into a plurality of tiles comprising a first tile and a second tile, wherein the first graphical feature spans the first tile and the second tile, and wherein the second graphical feature is located solely within the second tile; 
 partitioning the first graphical feature into a first fragment located solely within the first tile and a second fragment located solely within the second tile; 
 generating a first plurality of elemental vector objects for the first fragment; 
 adding the first plurality of elemental vector objects to a first display sub-list corresponding to the first tile; 
 generating a second plurality of elemental vector objects for the second fragment; 
 adding the second plurality of elemental vector objects and the second graphical feature to a second display sub-list corresponding to the second tile; 
 receiving a first request to scale the ED, wherein the first request specifies a resolution and a first region intersecting a subset of the tiles including the first tile but excluding the second tile; and 
 generating, in response to the first request, a first scaled ED for the display device by rendering the first display sub-list at the resolution without rendering the second display sub-list. 
 
     
     
       10. The non-transitory CRM of  claim 9 , the instructions further comprising functionality for:
 receiving a second request to scale the ED, wherein the second request specifies a second region intersecting the second tile; and 
 generating, in response to the second request, a second scaled ED for the display device by rendering the second display sub-list. 
 
     
     
       11. The non-transitory CRM of  claim 9 , wherein the instructions for rendering the first display sub-list comprise functionality for:
 traversing the first display sub-list and scaling the first fragment based on the resolution specified in the first request. 
 
     
     
       12. The non-transitory CRM of  claim 9 , wherein the first tile and the second tile have different areas. 
     
     
       13. The non-transitory CRM of  claim 9 , wherein the first display sub-list and the second display sub-list correspond to different sections of a master display list for the ED. 
     
     
       14. The non-transitory CRM of  claim 9 , the instructions further comprising functionality for:
 converting, before receiving the first request to scale the ED, the first fragment and the second fragment into a color space of the display device, wherein the first graphical feature is an image. 
 
     
     
       15. The non-transitory CRM of  claim 9 , wherein adding the second graphical feature to the second display sub-list comprises:
 generating, before receiving the first request to scale the ED, a vector outline for the second graphical feature, wherein the second graphical feature is a text character; and 
 adding the vector outline to the second display sub-list. 
 
     
     
       16. A system for scaling on a display device, comprising:
 a processor; 
 a buffer storing an electronic document (ED) identifying a first graphical feature and a second graphical feature; 
 a processing engine executing on the processor and configured to:
 partition the ED into a plurality of tiles comprising a first tile and a second tile; 
 partition the first graphical feature into a first fragment located solely within the first tile and a second fragment located solely within the second tile; 
 generate a first plurality of elemental vector objects for the first fragment; and 
 generate a second plurality of elemental vector objects for the second fragment; 
 
 a first sub-display list corresponding to the first tile and comprising the first plurality of elemental vector objects; 
 a second sub-display list corresponding to the second tile and comprising the second plurality of elemental vector objects; and 
 a rendering engine configured to:
 generate, in response to receiving a first scaling request, a first scaled ED for the display device by rendering the first display sub-list without rendering the second display sub-list, 
 wherein the first scaling request specifies a resolution and a region intersecting a subset of the plurality of tiles including the first tile and excluding the second tile. 
 
 
     
     
       17. The system of  claim 16 , wherein the ED is described in OOXML, and wherein the first tile and the second tile have different areas. 
     
     
       18. The system of  claim 16 , wherein the rendering engine is further configured to:
 generate, in response to receiving a second scaling request specifying a second region intersecting the second tile, a second scaled ED for the display device by rendering the second display sub-list. 
 
     
     
       19. The system of  claim 16 , wherein the first sub-display list and the second sub-display list correspond to different sections in a master display list for the ED. 
     
     
       20. The system of  claim 16 , wherein the processing engine comprises:
 an image module configured to:
 convert, before receiving the first scaling request, the first fragment and the second fragment to a color space of the display device, wherein the first graphical feature is an image; and 
 
 a text module configured to:
 extract a plurality of character data values from a font in the ED; 
 generate, before receiving the first scaling request, a vector outline for the second graphical feature in the ED based on the plurality of character data values, wherein the second graphical feature is a text character; and 
 add the vector outline to the second display sub-list.